The present invention relates to a power door locking system for an automotive vehicle. More specifically, the invention relates to an operating method and apparatus for operating the power door locking system to prevent false lock actuations.
Key operated power locking systems are known in which a key is inserted into a lock cylinder in the door and rotated. Early systems used a stricly mechanical system to unlock the dook through a link to the latch mechanism. In more recent cases an electrical system supplements or replaces the mechanical system. Using an electrical system, either the driver's side door or all the vehicle doors unlock by special action of the key. In some systems the key is rotated in one direction for one door to unlock and rotated in the opposite direction for all doors to unlock. In another system, the key is turned the same way in quick succession to unlock all the doors.
Typically, power lock systems use a simple sensor switch connected to the lock cylinder to complete a circuit. The appropriate locks of the vehicle unlatch according to the switch signal detected.
Such systems are, however, susceptible to false signals from the switch under certain conditions. Typically, locking systems use edge detection to sense the transition between two states. One cause of false sensing is caused from spurious electrical noise in the electrical system of the vehicle or induced voltages from external sources such as lightning that may be mistaken by the system to be a true signal, resulting in erroneous operation of the locking system. Another cause of false sensing is that moisture enters the lock and shorts the switch terminals within the locks together that also may result in erroneous operation of the locking system.
It would therefore be desirable to have a locking system capable of preventing false actuations due to erroneous signals.